1. Technical Field
The invention relates to drawer glide assemblies having a locking mechanism which prevents accidental disengagement of the drawer from the cabinet.
2. Background Art
It is well known to mount drawers in a cabinet on cooperating slide-and-roller assemblies. The slides are typically elongate channels having a U-shaped cross-section. The rollers are journaled on mounting brackets which extend from an end of the channel members so that the roller slidably engages the opposite track member when the drawers are inserted within the cabinet. Such drawer glide assemblies provide for easy movement of the drawer within the cabinet and minimize the amount of friction generated when the drawer is opened and closed.
It is also well known in the art to provide a means for limiting the distance by which the drawer may be withdrawn to prevent accidental disengagement of the drawer from the cabinet.
Such a drawer slide including a locking mechanism is disclosed in U.S. Pat. No. 3,995,927, issued Dec. 7, 1976, in which the channel includes a roller bracket carrying a pawl-like latch. The pawl is pivotably mounted on the bracket carried by the drawer channel and rides against the upper surface of the cabinet rail when the drawer is moved. In order for the drawer to be locked in place when it is extended, it is necessary for the pawl to rotate upwardly into a slot disposed on the upper rail of the cabinet channel.
U.S. Pat. No. 4,065,196, issued Dec. 27, 1977, discloses a drawer slide assembly having latching mechanism which is actuated by engagement with the drawer roller.
The locking mechanisms such as those disclosed above possess certain disadvantages. In U.S. Pat. No. 3,995,927, when the drawer is pulled outwardly after the panel engages the slot, a horizontally-directed force acts on the face of the pawl in the slot which tends to cause a counterclockwise pivoting of the latch. Accordingly, the pawl will tend to disengage from the slot. Additionally, a gravitationally actuated locking mechanism which requires the locking portion to be rotated upwardly into a slot may not be actuated due to deformation of the pawl or the accumulation of dirt around the pivot pin. The mechanism disclosed in U.S. Pat. No. 4,065,196 requires a positive force to be applied to the locking mechanism in order to prevent disengagement of the drawer.